This dissertation considers the interactions of users who have been diagnosed with Age-related Macular Degeneration (AMD), the leading cause of blindness in adults 65 years and older. The investigation focused on the quantification of behaviors and strategies used by this growing subset of computer users. Participants diagnosed with AMD and age-matched controls without any ocular disease completed a series of visual search, icon selection and manipulation tasks with desktop or handheld PCs. Participants searched, selected and manipulated familiar playing card icons under varied icon set sizes, inter-icon spacing, icon sizes and auditory feedback. A comprehensive account of the interaction was made using a collection of efficiency, accuracy and information processing metrics. While all participants demonstrated a high rate for successful task completion, analyses revealed participants' overall task efficacy to be coupled with features of the interface and also strongly linked with measures of ocular health and personal factors. The outcomes of this study contribute to a growing body of work which informs a framework of performance thresholds for critical graphical user interface interactions based on visual profile, interface features and supplemental non-visual cues, including the following: The impact of auditory feedback on task interaction and information processing for visually impaired versus visually healthy older adults; The observed of use of the mouse pointer or stylus as means to direct attention during visual search and the implications of manual dexterity on visual search; The presence of speed accuracy trade-offs in handheld PC interaction performance for individuals based on their contrast sensitivity and near visual acuity; The shifting impact of increased icon spacing on visual search and movement times, versus its role in the accuracy of icon release; The utility for non-clinically acquired summaries of visual health to effectively predict performance decrements in handheld or desktop interaction; Emergent differences between handheld and desktop interaction and the most influential visual factors informing performance on each; and Empirical evidence that older adults, even with visual impairments can interact with small handheld displays, in spite of the size images.

Age-related macular degeneration (AMD) is the leading cause for visual impairment and blindness in the elder population of developed countries. The primary underlying cause for significant visual loss is the choroidal neovascularization (CNV). Current treatment strategies for AMD include laser photocoagulation, photodynamic therapy (PDT) and excision of neovascular membranes, but have met with limited success. In our previous studies, we demonstrated that gene delivery of angiogenesis inhibitor vasostatin (VS) attenuated the corneal neovascularization in animals. The primary objective of this study was to investigate gene delivery of vasostatin (VS) attenuated the choroidal neovascularization in animals. Retinal and visual function will be evaluated. However, systematic expression of angiogenesis inhibitor may bring adverse effects to physiological processes. The feasibility, efficiency and safety of gene delivery with systemic and local routes were evaluated. Intramuscular polymer-based gene delivery had no side effect such as virus vector and revealed the safety. Recombinant adenovirus (Ad) was used gene delivery system because of its high titer, wide host range, and transduction efficiency. Adeno-associated virus (AAV) represents highly efficient that can facilirate long-term transduction. We propose to improve the efficacy and safety of VS gene delivery, and to search for the effective delivery route and other adjuvant therapy in conjunction with VS for treatment of CNV. Recently, PDT with veteporfin is an established treatment for subfoveal CNV secondary to AMD. We tried to compare the effect and safety of standard and reduced-dose light application PDT in an animal mocel of CNV. The 180-residue VS and its 48-residue (VS48) inhibited the migration and tube formation in cultured endothelial cells. Topical VS application suppresses the progression of laser-induced CNV via angiogenesis ihhibition, as well as in VS48. VS-48 inhibited the growthof vessels in arota rings. Electroretinograms (ERG) analysis revealed that topical VS-48 application for 21 days had no effect on rat retinal functions. Topical VS-48 treatment significantly reversed the CNV-induced alterations in ERG. Transfection of pCMV3-VS into muscle cells resulted in increased production and release of exogenous VS, which specifically inhibited the proliferation of endothelial cells. Rats treated with intrmuscular injection with PVP-VS also showed a significant reduction in the CNV lesions for at least 42 days. Subconjunctival injection with Ad vector revealed no retinal toxicity in ERG. Ad-luciferase via subconjunctival injections showed ocular expression for as long as 112 days by using bioluminescence image analysis in rodent. AAV-luciferase via subconjunctival injections showed ocular expression for as long as 365 days by using bioluminescence image analysis in mice, and AAV serotype 5-luciferase even showed expression lasting for 2 years. Suppression of laser photocoagulation¡Vinduced CNV by Ad-VS was documented in rat model. Combination therapies are important as treatment options. We demonstrated that PDT could effectively attenuate CNV in a rat model, and reduced doses, worked just as well as the standard dose. In the preliminary study of PDT combined topical VS application, treatment led to CNV attenuation more than alone with PDT. The above experiments would enable us to demonstrate that the vasostatin delivery might be a promising strategy for the treatment of AMD and other retinal or ocular disorders. Furthermore, the results from animal studies might be extrapolated for future clinical application.

Age-related macular degeneration (AMD) is the leading cause of blindness in the elderly worldwide. Due to the inadequacy of current pharmacotherapies, novel molecular targets must be sought as potential therapeutic candidates. Furthermore, there is a need for more efficient and cost-effective animal models of this pathology in order to accelerate in vivo investigations. / Our laboratory is in possession of human choroidal neovascular membranes which we examined for expression of cyclooxygenase (COX)-2. This expression was characterized in retinal pigment epithelial, vascular endothelial, and fibroblast cells and correlated with patient age. We also looked at the feasibility of creating a rabbit laser-injury model to adequately mimic human neovascular AMD. / Our results suggest that anti-COX-2 therapies may be beneficial to some patients with neovascular AMD. Moreover, there is strong potential for the development of clinically relevant choroidal neovascularization in rabbits using the laser-injury technique. This approach may yield a novel, cost-effective AMD model.

Age-related macular degeneration (AMD) is a principal cause of blindness in the United States and other industrialized nations. An estimated 10 million Americans are afflicted with AMD, which is comparable in scope to the 12 million living with cancer, or the 5 million with Alzheimer’s disease. The prevalence of AMD steadily increases with age, affecting 2% of the population at age 40, and one in four people by age 80. For reasons that are not fully understood, AMD is more common in lightly-pigmented and female populations. Treatment of AMD is largely an unmet need: There are no FDA approved therapies except for a small percentage of individuals with end-stage disease. This dissertation investigates the mechanisms of AMD pathogenesis and offers insight into novel therapeutic strategies for this disease.

ABSTRACT IMPORTANCE: Age-related macular degeneration (AMD) is a leading cause of low vision in elderly population. The association of vascular and renal conditions has been reported inconsistently. Unfolding the association may provide the insight to eye care providers to take account general health management into eye care. OBJECTIVES: To investigate the prevalence of the vascular and renal comorbidities with AMD, examine the association of a single or combination of these comorbidities with AMD. DSIGN AND PARTICIPANTS: Population-base cross-sectional study involved the adults aged 40 years or older (N=4596) who participated in the 2005 to 2008 National Health and Nutrition Examination Survey (NHANES), a national representative population-based survey of non-institutionalized US residents. MAIN OUTCOMES AND MEASURES: AMD was defined by the presence of drusen and presence of pigmental abnormality. Angina pectoris (AP), coronary heart disease (CHD), congestive heart failure (CHF) and myocardial infarction (MI), and stroke, assessed by self-report by the questionnaire of medical conditions, Chronic kidney disease (CKD), assessed by self-report and estimation of glomerular filtration rate (GFR) and the level of urine albumin. Heart disease (HD) was defined as having AP or CHF or CHD or MI. RESULTS: Among individuals with AMD, 6% had AP, 10% had CHD, 7% had CHF, 10% had MI, 13% had stroke, and 29% had CKD. The weighted prevalence of these conditions were significantly higher than those without AMD (All P-values CONCLUSION AND RELEVANCE: These findings from the nationally-representative sample of the US population highlight the prevalence of vascular and renal comorbidities associated with AMD, the modest evidence of relationship of each single comorbidity, and strong association of combination of stroke and CKD to AMD independent of age, gender, and other factors. Because of the cross-sectional design, the results of this study can not address a causal relationship between AMD and the examined comorbidities. It is unclear whether AMD and comorbidities arise from individual predisposition to vascular and renal diseases or whether complications from these morbidities increase the risk of AMD. However, the important caveat is that preventive and care management for the examined comorbidities may lessen the severity of symptoms or prevent AMD.

No description available.

Diss. (sammanfattning) Stockholm : Karol. inst., 2002. / CD-ROM i ficka. Härtill 5 uppsatser.

Age-related macular degeneration (AMD) is a prevalent cause of vision loss and irreversible blindness that affects more than 11 million Americans. AMD is a multifactorial disease with a number of genetic, demographic, and environmental risk factors. Currently the etiology of AMD is still unclear and there are no effective cure for this devastating disease, but recent studies have demonstrated that RORA is a candidate gene involved in AMD pathophysiology. RORA is a critical regulator of multiple biological processes and has been implicated in various physiological processes including circadian rhythm, lipid metabolism, photoreceptor development, autism, and inflammation. Our current study will explore in depth the role of RORA in AMD. We will look at the effects of RORA in the retina of mice. Localization studies of retinal tissues obtained from mice with a conditional knockout of RORA in epithelial cells showed little effect of RORA on structural cells of the retina. However, there was a decrease in VEGF and TGF-B proteins in RORA knockout. This is an interesting finding because VEGF and TGF-B has an important function in angiogenesis and neovascularization which are pathophysiological effects of AMD. In addition, we will try to identify gene targets of RORA that have also been linked with AMD. By identifying the targets of RORA and discovering how RORA regulates these targets, we hope to better understand the role of RORA in AMD pathophysiology. ChIP-seq and software analysis of the data was performed to identify all genomic targets of RORA linked with AMD. A number of promising genes were found in both RORA and AMD networks. The next step of this study is to perform quantitative analysis of these genes and how their expression is affected by RORA. Also, we will perform additional conditional RORA knockout models in cone cells and developing retinal cells to further understand the role of RORA in the retina and AMD pathogenesis.

In vitro disease models are powerful platforms for the development of drugs and novel therapies. Stem-cell based approaches have emerged as cutting-edge tools in disease modelling, allowing for deeper insights into previously unknown disease mechanisms. Hence the significant role of these disease-in-a-dish methods in therapeutics and translational medicine. Impedance sensing is a non-invasive, quantitative technique that can monitor changes in cellular behaviour and morphology in real-time. Bioimpedance measurements can be used to characterize and evaluate the establishment of a valid disease model, without the need for invasive end-point biochemical assays. In this work, two stem cell-based disease models-on-a-chip are proposed for acute liver failure (ALF) and age-related macular degeneration (AMD). The ALF disease model-on-a-chip integrates impedance sensing with the highly-differentiated HepaRG cell line to monitor in real-time quantitative and dynamic response to various hepatotoxins. Bioimpedance analysis and modelling has revealed an unknown mechanism of paracetamol hepatotoxicity; a temporal, dose-dependent disruption of tight junctions (TJs) and cell-substrate adhesion. This disruption has been validated using ultrastructural imaging and immunostaining of the TJ-associated protein ZO-1. Age-related macular degeneration (AMD) is the leading cause of blindness in the developed world with a need for disease models for its currently incurable forms. Human induced pluripotent stem cells (hiPSCs) technology offers a novel approach for disease modelling, with the potential to impact translational retinal research and therapy. Recent developments enable the generation of Retinal Pigment Epithelial cells from patients (hiPSC-RPE), thus allowing for human retinal disease in vitro studies with great clinical and physiological relevance. In the current study, the development of a tissue-on- a-chip AMD disease model has been established using RPE generated from a patient with an inherited macular degeneration (case cell line) and from a healthy sibling (control cell line). A reproducible Electric Cell-substrate Impedance Sensing (ECIS) electrical wounding assay was conducted to mimic RPE damage in AMD. First, a robust and reproducible real-time quantitative monitoring over a 25-day period demonstrated the establishment and maturation of RPE layers on microelectrodes. A spatially-controlled RPE layer damage that mimicked cell loss in AMD was then initiated. Post recovery, significant differences in migration rates were found between case and control cell lines. Data analysis and modelling suggested this was due to the lower cell-substrate adhesion of the control cell line. These findings were confirmed using cell adhesion biochemical assays. Moreover, different-sized, individually-addressed square microelectrode arrays with high spatial resolution were designed and fabricated in-house. ECIS wounding assays were performed on these chips to study immortalized RPE migration. Migration rates comparable to those obtained with ECIS circular microelectrodes were determined. The two proposed disease-models-on-a-chip were then used to explore the therapeutic potential of the antioxidant N-Acetyl-Cysteine (NAC) on hiPSC-RPE and HepaRG cell recovery. Addition of 10 mM NAC at the end of a 24h paracetamol challenge caused a slight increase in the measured impedance, suggesting partial cell recovery. On the other hand, no effect on case hiPSC-RPE migration has been observed. More experiments are needed to examine the effect of different NAC concentrations and incubation periods. The therapeutic potential of electrical stimulation has also been explored. A preliminary study to evaluate the effect of electrical stimulation on RPE migration has been conducted. An externally applied direct current electric field (DC EF) of 300 mV/mm was found to direct the migration of the immortalized RPE cell line (hTERT-RPE1) perpendicular to the EF. The cells were also observed to elongate and to realign their long axes perpendicular to the applied EF. The proposed tissue-on-a-chip disease models are powerful platforms for translational studies. The potential of such platforms has been demonstrated through revealing unknown effects of acetaminophen on the liver as well as providing deeper insights into the underlying mechanisms of macular degeneration. Combining stem cell technology with impedance sensing provides a high throughput platform for studying patient-specific diseases and evaluating potential therapies.

Orientador: José Paulo Cabral de Vasconcellos / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-24T03:32:34Z (GMT). No. of bitstreams: 1 Medina_FlavioMacCord_D.pdf: 2571030 bytes, checksum: 442e6e86f7bd3a0d6fae088740a1e85e (MD5) Previous issue date: 2013 / Resumo: Introdução: O fator de complemento H (CFH) é um componente do sistema imunológico que possui ação imunomoduladora sobre a resposta inflamatória. A gravidade da degeneração macular relacionada à idade (DMRI) é determinada em parte por um estado inflamatório sustentado por atividade aberrante da via alternativa do complemento. As evidências na literatura da relação entre o polimorfismo Y402H do gene CFH e a resposta ao tratamento da DMRI exsudativa permanecem controversas. Objetivo: Avaliar a associação entre as variantes do polimorfismo Y402H do gene CFH e os efeitos funcional e morfológico a curto prazo, assim como a evolução a longo prazo, dos antiangiogênicos em pacientes com DMRI exsudativa. Métodos: Vinte e cinco pacientes recém diagnosticados com DMRI exsudativa foram avaliados em um estudo de curto prazo com acuidade visual medida pela tabela do ETDRS e espessura retiniana central por tomografia de coerência óptica (OCT) de alta resolução, submetidos a injeção intravítrea de bevacizumabe e prospectivamente reexaminados em 7 e 28 dias. Quarenta e seis pacientes previamente submetidos ao tratamento com antiangiogênicos tiveram seus prontuários e exames retrospectivamente avaliados em um estudo de longo prazo quanto às evoluções funcional e morfológica ao longo de um ano. Esses parâmetros foram comparados com o genótipo do CFH, cuja análise molecular do polimorfismo Y402H foi realizada por meio da reação em cadeia da polimerase (PCR) e sequenciamento direto. Resultados: No estudo de curto prazo, houve melhora da acuidade visual no dia 28 em relação ao valor inicial (D0 vs. D28) em todos os genótipos. Entretanto, no grupo homozigoto para o alelo de risco (CC), ocorreu diferença apenas no dia 28 em relação ao dia 7 (D7 vs. D28), enquanto nos grupos CT e TT, a acuidade visual melhorou mais precocemente, no dia 7 em relação ao valor inicial (D0 vs. D7). A espessura retiniana central apresentou redução nos grupos CT (D0 vs. D7 e D0 vs. D28) e TT (D0 vs. D28), enquanto não houve mudança significativa no grupo CC. No estudo de longo prazo, foi evidenciada melhora da acuidade visual ao longo de um ano de acompanhamento apenas no grupo de pacientes sem o alelo C, sem diferença significativa no grupo de pacientes com o alelo de risco. A espessura retiniana central apresentou redução nos genótipos CT e TT, enquanto que no grupo CC não houve significância. Número de injeções, persistência de atividade neovascular e percepção subjetiva de melhora não diferiram entre os genótipos. Conclusão: O perfil de genótipo do CFH parece influenciar o efeito funcional e morfológico da injeção intravítrea de bevacizumabe com uma ação mais precoce em pacientes sem o genótipo de risco. A presença do alelo de risco parece estar relacionada à ausência de melhora visual ao longo de um ano de tratamento com inibidores do VEGF. Esses resultados sugerem que o perfil do genótipo do CFH possa exercer efeito farmacogenético nesse grupo de pacientes brasileiros, influenciando negativamente a resposta ao tratamento da DMRI exsudativa com antiangiogênicos / Abstract: Introduction: The complement factor H (CFH) is a component of the immune system that has immunomodulatory action on the inflammatory response. The severity of age-related macular degeneration (AMD) is determined in part by an inflammatory state sustained by aberrant activity of the alternative complement pathway. Evidences in the literature of the relationship between the Y402H polymorphism of CFH gene and response to treatment of wet AMD remain controversial. Purpose: To evaluate the association between variants of the Y402H polymorphism of CFH gene polymorphism and the short-term functional and morphological effects, as well as long-term evolution, of antiangiogenic drugs in patients with exudative AMD. Methods: Twenty-five patients with newly diagnosed exudative AMD were evaluated in a short-term study with visual acuity on ETDRS chart and central retinal thickness measured with high resolution optical coherence tomography (OCT), underwent intravitreal injection of bevacizumab and were prospectively reviewed in 7 and 28 days. Forty-six patients previously submitted to treatment with VEGF inhibitors had their medical charts retrospectively evaluated in a long-term study about the functional and morphological evolutions over one year. These parameters were compared with the CFH genotype, whose molecular analysis of Y402H polymorphism was performed by polymerase chain reaction (PCR) and direct sequencing. Results: In the short-term study, there was improvement in visual acuity at day 28 compared to baseline (D0 vs. D28) in all genotypes. However, in the group homozygous for the risk allele (CC), differences occurred only on day 28 compared to day 7 (D7 vs. D28), while the CT and TT groups, visual acuity improved earlier in the day 7 compared the initial value (D0 vs. D7). The central retinal thickness decreased in groups CT (D0 vs. D7, D0 vs. D28) and TT (D0 vs. D28), while there was no significant change in group CC. In the long-term study, it was noticed improvement in visual acuity over one year of follow-up in the group of patients without the C allele and no significant difference in the group of patients with the risk allele. The central retinal thickness decreased in the CT and TT genotypes, whereas in the CC group the difference was not significant. Number of injections, persistent neovascular activity and subjective perception of improvement did not differ between genotypes. Conclusion: The profile of the CFH genotype seems to influence the functional and morphological effect of intravitreal injection of bevacizumab with an earlier action in patients without the risk genotype. The presence of the risk allele seems to be related to the lack of visual improvement over one year of treatment with inhibitors of VEGF. These results suggest that the profile of the CFH genotype may present pharmacogenetic effect in this group of Brazilian patients, negatively influencing the response to treatment of exudative AMD with antiangiogenic drugs / Doutorado / Oftalmologia / Doutor em Ciências Médicas